1. Field of the Invention
The present invention relates to a method, and more particularly to a method of duplicating data to multiple random accessible storage devices.
2. Description of Related Art
Random accessible storage devices comprise flash memory storage devices. Universal Serial Bus (USB) flash drives, so-called Pen Drives or USB sticks, are widely used and popular commodities in today's society because it is rewritable and offers high volume to storage capacity ratio so it can be carried conveniently. Therefore, USB flash drives may be used as promotional gifts storing data, such as company information, merchandise catalogs or the like. However, if a large amount of USB flash drives with data is required, using a personal computer (PC) to copy data to many USB flash drives is an inefficient use of time.
A conventional USB flash drive duplicator is used to duplicate a large amount of USB flash drives and may be a synchronous duplicator or an asynchronous duplicator. Each duplicator has multiple USB connectors and a buffer. The USB connectors are used to connect respectively to target USB flash drives. The buffer is controlled to read the source data from a source medium and write the source data to the target USB flash drives through the USB connectors. In general, because the buffer has lower storage capacity than the source data, the source data is read and written in segments. Once a read segment of source data in the buffer has been written to the target USB flash drives, the USB flash drive duplicator will read the next segment of source data and overwrite the read segment in the buffer.
The synchronous duplicator requires all target USB flash drives to be plugged into the USB connectors on the duplicator before starting duplication and then the duplicator copies the source data from the first segment to the last segment in sequence to all target USB flash drives simultaneously. However, when copying data to large amounts of target USB flash drives, unplugging written target USB flash drives and plugging in unwritten target USB flash drives before starting duplication is time inefficient.
The asynchronous duplicator allows duplication to begin once a single target USB flash drive has been plugged in. Then, the asynchronous duplicator would duplicate the source data to subsequent target USB flash drives once connected and detected. A first conventional duplication method applied to the asynchronous duplicator is to divide the buffer into multiple sectors corresponding respectively to the USB connectors. Each sector of the divided buffer reads and writes the source data to a corresponding target USB flash drive to allow asynchronous duplication. However, the limited buffer needs to be divided into many sectors to handle asynchronous duplication with the first duplication method. As more target USB flash drives are connected asynchronously, more sectors of the buffer are required so asynchronous duplication is less efficient and considerably slower.
To solve the shortcomings of the first duplication method for asynchronous duplication, a second duplication method is taught, which requires the source data capacity to be equal to or smaller than the storage capacity of the buffer. The buffer finishes reading the whole source data before writing the source data to the target USB flash drives. When the target USB flash drives are asynchronously plugged into the USB connectors, the buffer proceeds to write the source data to the connected target USB flash drive without reading the source data. Therefore, the buffer operates at higher efficiency; however, raising a storage capacity of the buffer raises costs proportionately. Further, the second duplication method is limited to source data equal to or smaller than the storage capacity of the buffer. Therefore, use of duplicators applying the second duplication method are limited to source data smaller than the storage capacity of the buffer so that the use is limited. Further, as data storage becomes cheaper and data capacity of USB flash drives increases proportionately to cost, duplicators applying the second duplication method become obsolete and require replacement.
To overcome the shortcomings, the present invention provides a method of duplicating data to multiple random accessible storage devices to mitigate or obviate the aforementioned problems.